Sara Gilbert says that she realized she was a lesbian after making out with actor Johnny Galecki. And years down the line, Galecki said he'd still be happy to hold her hand.

Aww!

The revelation came Thursday on "The Talk," where all week the cohosts have been sharing well-kept secrets. (On Monday, Sharon Osbourne copped to a "flingy wingy" with Jay Leno when she was 25; Tuesday, Aisha Tyler revealed her struggles with fertility, and Wednesday, Julie Chen discussed the eye surgery she'd had years ago to Westernize her Asian look.)

When it was Gilbert's turn, she explained that while she was working on "Roseanne," she began dating Galecki, who played her boyfriend and then her husband on the show.

"I thought he was super cute and had a total crush on him," she said, "and we started dating and he would come over and we would make out and then I would start to get depressed."

Galecki, who's now on "The Big Bang Theory," felt bad and started to take it personally, Gilbert said, until she explained to him she thought it had to do with her sexuality -- she was coming to grips with being a lesbian.

After that, she said, he kept her secret close even as she began to date a woman 18 years her senior, who was also in the public eye.

"It was something people could have found out about and Johnny, like, no one knew at the show, for years, and Johnny held the secret the whole time," she said. "And I just felt so scared if it came out, what could happen. Could I lose my career? Would I ever be able to play a straight role again?"

Gilbert was clearly emotional as she told the story, as she often gets when discussing her sexuality and relationships on the show. She said that even though she's "thrilled" to be who she is and where she is in life, there's still a part of her that gets scared about being different.

She and Galecki are still in touch, so she said she called him to tell him she was going to discuss the issue on the show, and was he OK with that?

"The story sort of starts with you," Gilbert said she told him, "and you know I've got to say that I made out with you and got depressed, which is kind of a bummer!" She laughed.

"And he was like 'Yeah, no, of course' and 'I love you' and 'I think it's really important' and 'I'm so proud of you," and he said, you know, if you want I'll be there and I'll hold your hand.

Once again, aww.

"I just thought that was so sweet," she said, "and this story really makes Johnny look good."